//信息的类型 MSG_PING 心跳 、MSG_READY 链接就绪  MSG_MESSAGE 消息
export const MessageInfoType = {
    MSG_PING: "0",
    MSG_READY: "1",
    MSG_MESSAGE: "2"
};

/**
 * 心跳方式来自 https://gitee.com/lele-666/V-IM
 *
 * `WebsocketHeartbeatJs` constructor.
 *
 * @param {Object} opts
 * {
 *  url                  websocket链接地址
 *  pingTimeout 未收到消息多少秒之后发送ping请求，默认15000毫秒
    pongTimeout  发送ping之后，未收到消息超时时间，默认10000毫秒
    reconnectTimeout
    pingMsg ping 消息值
 * }
 * @api public
 */
function WebsocketHeartbeatJs({
    url="",
    pingTimeout = 20000000,
    // pingTimeout = 20000,
    pongTimeout = 15000000,
    // pongTimeout = 15000,
    reconnectTimeout = 5000000,
    // reconnectTimeout = 5000,
    pingMsg = '{"code": '+MessageInfoType.MSG_PING+'}'
}) {
    this.opts = {
        url: url,
        pingTimeout: pingTimeout,
        pongTimeout: pongTimeout,
        reconnectTimeout: reconnectTimeout,
        pingMsg: pingMsg
    };
    this.ws = null; // websocket实例

    // override hook function
    this.onclose = () => {};
    this.onerror = () => {};
    this.onopen = () => {};
    this.onmessage = () => {};
    this.onreconnect = () => {};

    this.createWebSocket();
}

WebsocketHeartbeatJs.prototype.createWebSocket = function() {
    try {
        this.ws = new WebSocket(
            this.opts.url
        );
        this.initEventHandle();
    } catch (e) {
        this.reconnect();
        throw e;
    }
};

WebsocketHeartbeatJs.prototype.initEventHandle = function() {
    this.ws.onclose = () => {
        this.onclose();
        this.reconnect();
    };
    this.ws.onerror = error => {
        this.onerror(error);
        this.reconnect();
    };
    this.ws.onopen = () => {
        this.onopen();
        // 心跳检测重置
        this.heartCheck();
    };
    this.ws.onmessage = event => {
        this.onmessage(event);
        // 如果获取到消息，心跳检测重置
        // 拿到任何消息都说明当前连接是正常的
        this.heartCheck();
    };
};

WebsocketHeartbeatJs.prototype.reconnect = function() {
    if (this.lockReconnect || this.forbidReconnect) return;
    this.lockReconnect = true;
    this.onreconnect();
    // 没连接上会一直重连，设置延迟避免请求过多
    setTimeout(() => {
        this.createWebSocket();
        this.lockReconnect = false;
    }, this.opts.reconnectTimeout);
};
WebsocketHeartbeatJs.prototype.send = function(msg) {
    this.ws.send(msg);
};
// 心跳检测
WebsocketHeartbeatJs.prototype.heartCheck = function() {
    this.heartReset();
    this.heartStart();
};
WebsocketHeartbeatJs.prototype.heartStart = function() {
    this.pingTimeoutId = setTimeout(() => {
        // 这里发送一个心跳，后端收到后，返回一个心跳消息，
        // onmessage拿到返回的心跳就说明连接正常
        this.ws.send(this.opts.pingMsg);
        // 如果超过一定时间还没重置，说明后端主动断开了
        this.pongTimeoutId = setTimeout(() => {
            // 如果onclose会执行reconnect，我们执行ws.close()就行了.如果直接执行reconnect 会触发onclose导致重连两次
            this.ws.close();
        }, this.opts.pongTimeout);
    }, this.opts.pingTimeout);
};
WebsocketHeartbeatJs.prototype.heartReset = function() {
    clearTimeout(this.pingTimeoutId);
    clearTimeout(this.pongTimeoutId);
};
WebsocketHeartbeatJs.prototype.close = function() {
    // 如果手动关闭连接，不再重连
    this.forbidReconnect = true;
    this.ws.close();
};
if (window) window.WebsocketHeartbeatJs = WebsocketHeartbeatJs;
export default WebsocketHeartbeatJs;

